Database Reference
In-Depth Information
Other list operations
We've seen that the structure of maps and sets allows Cassandra to perform all supported
mutation operations on those collection types without having to read the currently stored
values. Unfortunately, the same is not true for lists. While appending and prepending to
lists can be done discretely, other operations require scanning the existing contents of the
list first.
If we take a moment to ponder the underlying representation of list columns, the reason is
clear. If, for instance, we ask to remove the value
dave
from the list, there's no way for
Cassandra to know which cell(s) contain that value without reading it. Even in the simpler
case of deleting an element at a given position, Cassandra must look at the cell names to
know which cell is at the position requested. So, it's worth keeping in mind that list muta-
tions—except for appending and prepending—are naturally less performant than mutations
on other collection types.
